sub property1 {
    my ($self, $value) = @_;
    @_ >= 2 and $self->{property1} = $value;  # update: s/>/>=/
    $self->{property1};                       # update: s/property/property1/
}
sub property2 {
    my ($self, $value) = @_;
    @_ >= 2 and $self->{property2} = $value;  # update: s/>/>=/
    $self->{property2};                       # update: s/property/property2/
}